Device intended preferably for sterilizing web-like packaging materials



A. TUMA 3,511,592 DEVICE INTENDED PREFERABLY FOR STERILIZING WEBLIKE May12, 1970 PACKAGING MATERIALS 2 Sheets-Sheet 1 Filed Aug. 5. 1966INVENTOR ALEX TUMA BY Q JL W ATTORNEY May 12, 1970 A. TUMA 3,511,592DEVICE INTENDED PREFERABLY FOR STERILIZING WEB-LIKE PACKAGING MATERIALSFiled Aug. 3, 1966 2 Sheets-Sheet 2 Fig. 2

INVENTOR ALEX T UM A BY f m; [Z W- ATTORNEY United States Patent US. Cl.21-92 4 Claims ABSTRACT OF THE DISCLOSURE Apparatus to sterilize a webof packaging material having inner and outer containers which define along narrow slot therebetween for the sterilizing liquid through whichpasses the web of material.

The present invention relates to a device for treating preferablyweb-like materials. More particularly, it relates to a device forsterilizing web-like packaging materials. The device comprises an outercontainer holding a certain quantity of processing liquid.

An object of the invention is to provide a device having small outerdimensions and holding a minimum of processing liquid but comprising along processing path for the material to be moved through the device.

The device is characterized by an inner filling body having essentiallythe same shape as the outer container and intended to displace part ofthe processing liquid so that a long slot-shaped space filled withprocessing liquid is provided between the outer container and thefilling body, in which the web material is meant to be advanced.

In the preferred embodiment the invention is further characterized inthat the outer container has a considerable depth in relation to itsother dimensions. At the sterilizing of material by means of thesterilizing liquid held in the outer container a considerably increasedsterilizing elfect is obtained as a consequence of the static pressurein the lower portion of the outer container caused by the weight of theliquid.

Furthermore, the invention offers a possibility to heat the sterilizingliquid in a simple manner to a desired relatively high temperature,whereby the sterilizing effect is further intensified. This can beachieved by heating the filling body, whereby the said body due to thecontact with the processing liquid is ableto heat the liquid andmaintain it at the desired temperature.

Further objects and advantages of the invention will be apparent fromthe accompanying drawings showing a preferred embodiment, chosen by wayof example, of the invention according to the application, and whereFIG. 1 is a diagrammatic section of a sterilizing device in anoperational position connected to a packaging machine, and

FIG. 2 shows the same device with its main parts separated from eachother.

In the drawings, reference numeral 1 designates an outer containerholding a relatively small volume of sterilizing liquid 3, preferablyconsisting of hydrogen peroxide H 0 of 35 percent, although othersterilizing liquids than H 0 may also be used. The outer container 1 isslightly wedge-shaped and has a considerable depth in relation to itswidth. The expression width designates the width of the device as shownin the drawings.

Furthermore the device comprises a filling body 2 which in the positionof preparedness shown in FIG. 2 is located above the outer container 1and in FIG. 1 inside the outer container 1. The filling body 2 consistsof a hollow body filled with water 8. The water can be ice heated bymeans of a heating spiral 9. Reference numeral 14 designates connectinglines for the heating coil 9.

As mentioned, the device is intended for sterilizing a Web-likepackaging material, the device being disposed in connection with apackaging machine designated 10 in FIG. 1. In the machine 10 theweb-like packaging material 16, after being wound off from a storageroll 15 and being sterilized in the sterilizing device, is reshaped intoa tube which is filled under aseptical conditions with the intendedfilling material and shaped into separate packages. In order toguarantee complete sterility it is necessary to keep the atmosphere inthe packaging machine completely sterile. In order to achieve this thereis maintained a certain pressure above atmospheric of sterile air insidethe machine so that air containing microorganisms cannot penetrate intothe machine from the surrounding atmosphere. However, there is still arisk for infection on account of the inlet opening of the packagingmaterial in the machine. This is due to the fact that through therelatively large translation rate of the packaging material there isformed an air current parallel to the material. Under these conditionsthe rate of flow of the air may be so large that it will overcome thepressure inside the machine and will introduce microorganisms into thesterile atmosphere. In order to prevent this there is disposed a sleeve11 through which the packaging material 16 is meant to be conducted intothe machine 10. The sleeve 11 is of such a length that in theoperational position of the sterilizing device (of FIG. 1) it is loweredwith its inlet orifice 12 into the sterilizing liquid 3. This provides aliquid lock eifectively preventing the surrounding atmosphere frompenetrating into the interior of the machine 10 through the inletopening of the packaging material 16, and preventing the sterile gasfrom flowing out into the free air, which is of economical importance.

Other means shown in the drawings consist of a first pulley 4 journalledin holding means 5 which are connected with the outer container 1. Thereis further provided a second pulley 6, which is connected with thefilling body 2 by holding means 7. Finally, reference numeral 13designates a member for clamping fast the filling body 2. The said body2 is consequently stationary, while the outer container 1 isdisplaceable between the positions shown in both drawings. The means foroperating the outer container 1 have not, however, been shown in thedrawings, which is not either necessary for understanding the principlesof the invention. The device shown operates in a manner which will bedescribed in the following. For this purpose it is assumed that thedevice originally occupies a position of preparedness, FIG. 2, in whichconnection the web of material 16 is led over the pulley 4, below thepulley 6 and moved up through the sleeve 11 into the machine 10. In theouter container 1 there is a small volume of hydrogen peroxide H 0 atroom temperature. In a manufactured device the volume of H 0 is about3.5 litres. The sterilizing liquid is then at the level designated 18.The water 8 located in the filling body 2 is heated to boilingtemperature C. In the manufactured device the water volume amounts toabout 10.5

itres.

When the machine 10 is to start the outer container 1 is moved upwardtoward the filling body 2 by means of members not shown in the drawings.By means of the pulley 6 the web of material 16 is pressed down againstthe bottom of the outer container 1 as a consequence of the relativemotion 2 between the two members 1 and 2. The filling body 2 displacesthe liquid 3 so that along the greater part of the length of the devicethere only remains a narrow slot of liquid, in which slot the web ofmaterial 16 is meant to be advanced. As a consequence of thedisplacement the liquid 3 will occupy a higher level 17, which liesabove the orifice 12 of the sleeve 11.

Due to the fact that the volume content of the filling body 2 isconsiderably larger than the quantity of sterilizing liquid 3, thelatter 'willbe heated very quickly. This applies in particular to theliquid in the slot-shaped space between the outer vessel 1 and thefilling body 2, which is heated, under the influence of the intimatecontact with the hot filling body, essentially momentarily toa'temperature acceptable for obtaining a good sterilizing effect. Inorder to increase the sterilizing effect still further, the bath may ofcourse be heated by means of the heating coil 9.

At the sterilizing operation the web of material 16 is fed from thestorage roll 15, via the pulley 4 down into the sterilizing bath, belowthe lower pulley 6, up through the sterilizing bath and into the packingmachine through the sleeve 11, which serves as a liquid lock.

During the passage through the liquid bath the web of material 16 isexposed to a combined chemical-thermal sterilizing operation. Thiscombination has turned out to be more effective than a chemical andthermal sterilizing operation carried out separately. Due to the: factthat the device has a considerable depth, the sterilizing efiectincreases still further. This is caused by the static pressure in thebottom portion of the device, which intensifies the contact between themicroorganisms to be rendered harmless and the sterilizing liquid. Inaddition, as a result of the embodiment of the device a relatively longprocessing time is achieved, which in the present case amounts to about12 seconds.

Because of the transport of the web of material 16 through thesterilizing bat-h there arises, of course, a certain flow of liquid.This consists on one hand of a current parallel to the web of materialand on the other of a reflux from the right-hand side of the device toits left-hand side as seen in FIG. 1. However, there is no flow from theleft to the right, which is important since this eliminates the riskthat microorganisms will move through the sterilizing liquid theshortest path from the point where the web of material 16 is immersedinto the bath up to the orifice 12 of the sleeve 11.

The position shown in FIG. 2 has been termed position of preparedness inthe preceding text. A more adequate expression is material introducingposition, for this position is only occupied when the packaging materialis to be introduced into the machine. During breakdowns or when thesterilizing operation has to be stopped for other reasons it issuflicient to lower the outer vessel 1 only a relatively short distance,viz in such a way that the packaging material will be located completelyabove the liquid surface 18. Thereby the device can very quickly bereturned to its operational position, i.e., the position shown in FIG.1.

The device described above is shown with a stationary filling body and amobile outer container. It wi l be realized, however, that it is alsopossible to make the outer container stationary and the filling bodymobile and to make both means mobile in relation to each other.

It should be also possible to treat other materials than those in thenature of webs in the shown device. This may for instance be achieved bydisposing the objects to be treated between two endless belts carryingthe objects through the device.

Yet another modification is to use heated oil or another liquid in thecontainer 2 instead of water. This makes it possible to obtain aconsiderably higher temperature of the body to be immersed into thesterilizing bat-h. It is also possible to use a completely stationarybody having good heat-conductive properties.

Also other modifications of the device shown will be possible to achievewithout exceeding the scope of the inventive idea. The invention isconsequently not limited to the embodiment shown but is only limited bythe subsequent claims.

That which is claimed is:

1. A device for sterilizing a Web of packaging material comprising: anouter elongated container adapted to hold a certain volume of processingliquid, an inner container of substantially the same shape as the outercontainer telescoped in said outer container and forming an elongatedslot therebetween, said outer container and said inner container beingdisplaceable relative to each other to vary the size of said slot.

2. A device intended preferably for sterilizing weblike packagingmaterials, comprising an outer wedgeshaped container holding a certainvolume of processing liquid, characterized by an inner wedge-shapedfilling body having essentially the same shape as the outer containerand intended to displace part of the processing liquid so that a longspace in the shape of a slot and filled with processing liquid isprovided between the outer container and the filling body, in which theweb-like material is meant to be advanced.

3; A device for sterilizing a web of packaging material comprising: anouter wedge-shaped elongated container "adapted to hold a certain volumeof processing liquid, an inner Wedge-shaped container of substantiallythe same shape as the outer container telescoped in said outer containerand forming an e ongated slot therebetween, said outer container andsaid inner container being disp1ace able relative to each other to varythe size of said slot.

4. The structure of claim 3 wherein said inner container has a pulley onthe bottom end thereof.

References Cited UNITED STATES PATENTS 1,306,650 6/1919 Weinheim 118-429XR 1,389,630 9/1921 Cooney 118-419 XR 2,168,997 8/1939 Lankes et a1.118-419 3,163,971 1/1965 Loliger et a1. 21-2 XR 3,215,115 11/1965 Knightet a1. 118-429 XR 207,008 8/1878 Bryant 220-17 XR 232,026 9/ 1880Hayward 220-17 MORRIS O. WOLK, Primary Examiner D. G. MILLMAN, AssistantExaminer U.S. Cl. X.R. 21-58, 99; 118-419

